1. Field of the Invention
The invention relates to a device for leakage detection and leakage location in an installation, in particular in a pipeline, including a collecting line which is permeable to a substance and is connected to a pump and to a sensor for the substance. The invention also relates to a method for leakage detection and leakage location in an installation, in particular in a pipeline, which includes detecting and locating a concentration maximum of a substance which has penetrated into a permeable collecting line.
German Patent 24 31 907 discloses a leakage detection and location system (LEOS). That system contains a collecting line which is permeable to substances that are to be detected. Volumes of a transport medium which is air, for example, can be conveyed one after another through the collecting line by a pump connected to the collecting line. At least one sensor which is disposed at the end of the collecting line detects substances that have penetrated into the collecting line. The collecting line is disposed in the vicinity of an installation to be monitored, in particular along a pipeline. In the event of a leak in the installation or in the pipeline, the substance that has emerged from the leak then passes to the collecting line and penetrates into the collecting line. As a result, a concentration maximum of the substance forms in the vicinity of the leak, in the collecting line which is laid there. During the next pumping operation of the leakage detection and location system, that concentration maximum passes to the sensor. The location of the leakage can be determined from the time which elapses between switching on the pump and the sensor responding.
That known system can be used only when the installation to be monitored contains a substance which on one hand can penetrate into the collecting line, and on the other hand can be detected by a sensor.
European Patent 0 525 593 B1, corresponding to U.S. Pat. No. 5,271,901, discloses a device with which acid that has emerged from a leak can be detected and the leak can be located, during the use of the leakage detection and location system (LEOS). That is possible as a result of the fact that a material which reacts chemically in the event of contact with the acid, forming a detectable substance to which the collecting line is permeable, is placed in the vicinity of the collecting line. That material may be zinc, in particular a zinc wire. That is because zinc reacts with acid, forming hydrogen, which can be detected in a simple way by using the known leakage detection and location system.
Heretofore, it has not been possible to use the known leakage detection and location system to detect solutions which have emerged from a leak and may be neutral or even alkaline. Such a solution, which is transported through a pipeline, may be salt water, for example. During the production of underground gas reservoirs for natural gas, it is specifically often necessary to remove salt water which contains up to 300 g of salt per liter. For that reason, it is often necessary for a salt-water line to be led over very great distances, for example as far as the sea. Since the salt water can damage plants, it is necessary to monitor those salt-water lines, in order to be able to detect and locate a leak rapidly and reliably.